1. Field of the Invention
The present invention relates to a magnetic sensor and a magnetic balance type current sensor utilizing the magnetic sensor.
2. Description of the Related Art
In an electric vehicle, a motor is driven using electricity generated by an engine, and the intensity of the current for driving the motor is detected by, for example, a current sensor. The current sensor includes a magnetic core disposed around a conductor and having a cutaway portion (core gap) formed at a portion thereof, and a magnetic detecting element disposed within the core gap.
As the magnetic detecting element of the current sensor, a magnetoresistance effect element (GMR element or TMR element) including a laminate structure having a fixed magnetic layer with a fixed magnetization direction, a non-magnetic layer, and a free magnetic layer with a magnetization direction varying with respect to an external magnetic field, or the like is used. In such a current sensor, a full-bridge circuit is configured using a magnetoresistance effect element and a fixed resistance element. In this case, it has been disclosed that a fixed resistance element of a type is used that includes a film configuration where the lamination order of a free magnetic layer and a non-magnetic layer of a magnetoresistance effect element is changed, the fixed resistance element fixing the magnetization of a ferromagnetic layer using an antiferromagnetic material. Such a technique is disclosed in Japanese Unexamined Patent Application Publication No. 2007-248054 or Japanese Unexamined Patent Application Publication No. 2007-263654. By adopting such a configuration, it may be possible to cause electrical resistances or temperature coefficient resistivities (TCRs) of the magnetoresistance effect element and the fixed resistance element to coincide with each other and it may be possible to obtain a certain level of a stable output characteristic even if an ambient temperature has changed.